cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

Showing 1-2 of 2 results.

A074655 Number of Lyndon words (aperiodic necklaces) with 3n beads of 3 colors, n beads of each color.

Original entry on oeis.org

1, 2, 14, 186, 2880, 50450, 952854, 19003474, 394394880, 8439756660, 185033201150, 4137181680698, 94020326259264, 2166105078791446, 50489825369325118, 1188777328563863850, 28236363841594782720, 675879582290807439794, 16289254212695836475436
Offset: 0

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Author

Christian G. Bower, Aug 29 2002

Keywords

Crossrefs

Cf. A029808, A074651, A022553 (2n of 2 colors), A074656 (4n of 4 colors).

Formula

a(n) = 1/(3n) * Sum_{d|n} mu(n/d) * (3d)! / d!^3, a(0) = 1.
a(n) = A029808(n)*2 = A074651(n)/3.

Extensions

a(0)=1 prepended by Alois P. Heinz, Aug 24 2015

A006174 Witt vector *3!.

Original entry on oeis.org

6, 27, 488, 7974, 149796, 2725447, 56970432, 1151053821, 25279412332, 543871341927, 12411512060544, 278163517356594, 6498314231705568, 149846653983570795, 3565206002960088128, 84045618111578025105
Offset: 1

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Author

Keywords

Comments

If c is the Witt transform of b then b(n) = Sum_{d|n} A074650(n/d, c(d)).

References

  • N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

Formula

Witt transform of A074651.

Extensions

More terms and formula from Christian G. Bower, Aug 28 2002
Showing 1-2 of 2 results.